1. Field of the Invention
The present invention is directed to a method for replacing sub-systems which are components of larger systems, wherein the sub-systems are subject to technological aging, i.e., the sub-systems become outdated.
2. Description of the Prior Art
Many large systems employ a number of sub-systems as components of the system, and the sub-systems are subject to relatively rapid technological aging, i.e., the sub-systems become outdated in terms of technology much more quickly than the overall system. This means that one or more sub-systems will almost always have to be replaced before the overall system becomes obsolete and is itself in need of replacement. In the case of personal computers which form a sub-system of a larger system, the rapid advances in computer technology and software updates make it certain that the personal computer which is present in the system at the time of installation will have to be replaced, probably several times, during the life of the system.
In the case of a medical imaging system, such as a computed tomography apparatus or a magnetic resonance imaging apparatus, for example, the overall life of the system may be approximately ten years, whereas the operating computer in such a system will have a typical technological service life of, for example, three years. This technological service life for the personal computer is established by the time during which individual replacement parts are available, as well as by the duration of the acceptable performance of the computer. When either replacement parts are not available, or it is determined that the computer""s performance is so far below current standards as to present a drag or burden to the system, replacement of the computer is necessary. Of course, if a malfunction occurs at or before this time, replacement is also necessary.
Many customers, however, are resistant to continually replacing or updating computers which are integrated into a larger system. In order to accommodate these desires on the part of many customers, manufacturers, or those responsible for fulfilling maintenance and service contracts, must maintain a relatively large inventory of replacement parts available. With regard to software upgrades, many customers are reluctant to pay the additional cost associated with a software upgrade and, moreover, it must be ensured that the upgraded software still allows proper functioning when installed in a computer which is a subsystem of an older system.
It is an object of the present invention to provide a method for replacing technologically aging sub-systems in a system which allows customers with a maintenance agreement to have a system with a defined technological age and which allows customers who do not have a maintenance agreement to incur costs in the event of a malfunction of a sub-system that were predictable in advance.
This object is inventively achieved in a method wherein sub-systems that rapidly age in terms of technology are divided into a finite number of age levels. An upgrade path is defined and applied for each age level.
In the inventive method, a central customer databank is maintained in which age classes of the sub-systems for a number of different customers are maintained. For each sub-system and for each customer, such age classes are maintained in the databank both for hardware and software. Before repair or replacement of a hardware component, the databank is interrogated to determine whether, for the sub-system in question and the customer in question, a complete hardware (sub-system) replacement is appropriate, given the age class of the sub-system currently installed at the customer. If a complete sub-system replacement with the newest sub-system generation is determined to be appropriate and is thus undertaken, the customer databank is updated to indicate the new sub-system generation which is now installed at the customer. Similarly, before a software upgrade is undertaken for a particular customer, the databank is interrogated to determine whether a complete hardware replacement for the sub-system in question, given age class of the sub-system and the software, is appropriate, and if so the hardware and the software at the customer are updated and the customer databank is also updated to indicate the sub-system newest generation software that are now installed at the customer.
In dividing the hardware of the sub-system into age classes all sub-systems which are based on the same technology characterized, for example, by the same type of memory chip, same type of processor, same level of integrated circuit design, etc., are classified in the same age class.